Heretofore, conventional trailer vans have included rigid end, side and roof walls with access openings in the side walls and/or in the rear end wall. While these vans have been satisfactory for protecting their cargo from inclement weather, they have been characterized by certain inherent disadvantages such as, limited access to the interior of the van for loading and unloading; the limited use of the storage space within the van due to the rigid walls; and high cost in the manufacture of the van.
To overcome some of the disadvantages of conventional vans, flat bed trailers have been employed with the cargo being covered by a tarpaulin. While these trailers provide easy access for loading and unloading, the tarpaulin has not provided the cargo with adequate protection from the elements, and the size and weight of the tarpaulin has made it difficult, if not impossible, for one man to handle.
After considerable research and experimentation, the trailer van of the present invention has been devised to include the advantages of conventional vans and tarpaulin covered trailers while eliminating the disadvantages therein. The trailer van of the present invention includes vertically extensible roof, side and end walls disclosed generally in the following U.S. Pat. Nos.: 2,797,124 -- Jun. 25, 1957 -- Haupti, 3,098,456 -- Jul. 23, 1963 -- Elsner, 3,140,116 -- Jul. 7, 1964 -- Speas, 3,160,436 -- Dec. 8, 1964 -- Duddleston, 3,319,994 -- May 16, 1967 -- Smock, 3,694,024 -- Sep. 26, 1972 -- Linville.
The expandable trailer van of the present invention being an improvement over the expandable vehicle bodies disclosed in the above-noted patents in that the roof, and side walls are formed of flexible material forming a tarpaulin whereby the roof and side walls are adapted to conform to the cargo being transported, and the edge of the tarpaulin is tightly held against the trailer frame to provide an adequate seal to protect the cargo during the transport thereof.